Although hyperdynamic therapy is an accepted method of treatment of patients with symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage, it remains unproven in large scale trials and controlled studies. Furthermore, methods of hyperdynamic therapy and specific endpoints vary widely. A systematic review of clinical trials of the various techniques of hyperdynamic therapy and their effects on cerebral blood flow found only 11 studies suitable for analysis. Although controlled trials are lacking, there is some evidence to suggest that hypertension is the most promising component of hyperdynamic therapy. These findings support a future randomized trial of induced hypertension in patients with symptomatic cerebral vasospasm.© 2010 BioMed Central Ltd.